Balanced development of piezoelectricity and Curie temperature in (1 − x)K0.44Na0.52Li0.04Nb0.96Sb0.04O3–xBi0.25Na0.25Ba0.5ZrO3 lead-free piezoelectric ceramics

• Published in: Journal of materials science. Materials in electronics 2018, Vol.29 (2), p.1341-1348
• Main Authors: Xu, Zhi-Xue, Yan, Jian-Min, Guo, Lei, Xu, Meng, Wang, Fei-Fei, Liu, Yu-Kuai, Zheng, Ren-Kui
• Format: Article
• Language: English
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Concentration (composition); Curie temperature; Dielectric properties; Diffraction; Diffraction patterns; Doping; Ferroelectric materials; Ferroelectricity; Lead free; Materials Science; Optical and Electronic Materials; Phase volume fraction; Piezoelectric ceramics; Piezoelectricity; Solid phases
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-017-8040-x

(1 −  x )K 0.44 Na 0.52 Li 0.04 Nb 0.96 Sb 0.04 O 3 – x Bi 0.25 Na 0.25 Ba 0.5 ZrO 3 [(1 −  x )KNLNS- x BNBZ] (0 ≤  x  ≤ 0.05) lead-free piezoelectric ceramics were prepared by using the conventional solid-state reaction method. The relationships among the composition, phase structure, phase volume fraction, microstructure, dielectric, ferroelectric, and piezoelectric properties as well as the phase diagram are established. Rietveld refinements of X-ray diffraction patterns show that with increasing doping level the volume fractions of the orthorhombic and tetragonal phases evolve from 58.7 and 41.3% for x  = 0 to 1.7 and 98.3% for x  = 0.05, which has strong impacts on the piezoelectric coefficient d 33 and Curie temperature T C . Upon the doping of BNBZ an orthorhombic-tetragonal ( O – T ) phase boundary forms near room temperature, resulting in an optimum d 33 ~ 288 pC/N, T C ~ 305 °C, a converse piezoelectric coefficient d 33 * ~ 391 pm/V, and a field-induced strain S ~ 0.156% for the x  = 0.035 ceramics. These results demonstrate that a balanced development of d 33 and T C can be realized by choosing suitable doping materials and content.